lamellar bone
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2021 ◽  
Vol 12 ◽  
Author(s):  
Yi Zhan ◽  
Bing Deng ◽  
Huixian Wu ◽  
Changpeng Xu ◽  
Ruiying Wang ◽  
...  

Liquid crystals (LCs) are appealing biomaterials for applications in bone regenerative medicine due to their tunable physical properties and anisotropic viscoelastic behavior. This study reports a novel composite poly (L-lactide) (PLLA) scaffold that is manufactured by a simple electrospinning and biomineralization technique that precisely controls the fibrous structure in liquid LC phase. The enriched-LC composites have superior mineralization ability than neat PLLA; furthermore BMSC cells were inoculated onto the HAP-PLLA/LC with hydroxyapatite (HAP) composite scaffold to test the capability for osteogenesis in vitro. The results show that the PLLA/LC with HAP produced by mineralization leads to better cell compatibility, which is beneficial to cell proliferation, osteogenic differentiation, and expression of the angiogenic CD31 gene. Moreover, in vivo studies showed that the HAP-PLLA/LC scaffold with a bone-like environment significantly accelerates new and mature lamellar bone formation by development of a microenvironment for vascularized bone regeneration. Thus, this bionic composite scaffold in an LC state combining osteogenesis with vascularized activities is a promising biomaterial for bone regeneration in defective areas.


Background: Repair of broken bones due to physiological or pathological factors has always been important for researchers. In this regard, this study aimed to evaluate the effect of a combined extract on the osteogenic process in the experimental fracture created in the femoral of rats as laboratory models. Materials and Methods: This experimental study was performed on 21 rats. After induction of general anesthesia to each mouse, a 3-cm incision was made in the femoral bone and it was broken with a special hammer. After surgery, the control group did not receive any extract, while the three experimental groups received 200, 500, and 1000 mg/kg PO, respectively. In the next step, 21 days after surgery, euthanasia was performed and bone sections were prepared and stained in the fracture site. Next, histopathological and histomorphometric studies were carried out for the evaluation of bone healing in rats. The collected data were analyzed in SPSS software (version 21). Results: According to the pairwise comparison test, the mean difference of variables, namely bone marrow, woven bone, and lamellar bone of the third group of the test was significantly different from those of the other groups (P<0.05). This indicated that receiving the extract in the experimental groups with an increased dose led to a decrease in the mean bone marrow and woven bone which, in turn, increased the mean lamellar bone. Conclusion: The results showed that the combined extracts of mummy, Withania coagulans, and turmeric can stimulate osteogenesis in rats and be considered as a candidate for fracture treatment.


Author(s):  
Cinzia Peruzzi ◽  
Rajaprakash Ramachandramoorthy ◽  
Alexander Groetsch ◽  
Daniele Casari ◽  
Philippe Grönquist ◽  
...  

Author(s):  
Dr. Daniele Casari ◽  
Tatiana Kochetkova ◽  
Dr. Johann Michler ◽  
Prof. Philippe Zysset ◽  
Dr. Jakob Schwiedrzik

Author(s):  
Michael Conward ◽  
Johnson Samuel

Abstract This two-part paper is aimed at developing a microstructure-based mechanistic modeling framework to predict the cutting forces and acoustic emissions generated during bone sawing. The modeling framework is aimed at the sub-radius cutting condition that dominates chip-formation mechanics during the bone sawing process. Part-1 of this paper deals specifically with the sawing experiments and modeling of the cutting/thrust forces. The model explicitly accounts for key microstructural constituents of the bovine bone (viz., osteon, interstitial matrix, lamellar bone, and woven bone). The cutting and thrust forces are decomposed into their shearing and ploughing components. Microstructure-specific shear stress values critical to the model calculations are estimated using micro-scale orthogonal cutting tests. This approach of estimating the microstructure-specific shear stress overcomes a critical shortcoming in the literature related to high-strain rate characterization of natural composites, where the separation of the individual constituents is difficult. The six model coefficients are calibrated over a range of clinically relevant depth-of-cuts using pure haversian regions (comprising of osteon and interstitial matrix), and pure plexiform regions (comprising of lamellar bone and woven bone). The calibrated model is then used to make predictions in the transition region between the haversian and plexiform bone, which is characterized by gradient structures involving varying percentages of osteon, interstitial matrix, lamellar bone, and woven bone. The mean absolute percentage error in the force predictions is under 10 % for both the cutting and thrust forces.


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 143
Author(s):  
Hiroki Katagiri ◽  
Yacine El Tawil ◽  
Niklaus P. Lang ◽  
Jean-Claude Imber ◽  
Anton Sculean ◽  
...  

The aim of this study was to evaluate the influence of additional hydroxyapatite (HA) in collagen-based matrices (CM) and membrane placement on bone formation in calvarial defects. Critical size defects in the calvaria of 16 New Zealand White Rabbits were randomly treated with CM or mineralized collagen-based matrices (mCM). Half of the sites were covered with a collagen membrane. Animals were euthanized after 12 weeks of healing. The samples were studied by micro-CT and histology. Newly formed lamellar bone was observed in all samples at the periphery of the defect. In the central areas, however, new bone composed of both woven and lamellar bone was embedded in the soft tissue. Samples treated with mCM showed more residual biomaterial and induced more small bony islands in the central areas of the defects than samples with CM. Nevertheless, a complete defect closure was not observed in any of the samples at 12 weeks. Membrane placement resulted in a decrease in bone density and height. Significant differences between the groups were revealed only between CM groups with and without membrane coverage for bone height in the central area of the defect. Neither mineralization of CM nor membrane placement improved the osteogenic capacity in this particular defect. Nevertheless, mineralisation influenced bone density without a membrane placement and bone volume underneath a membrane. CM may be used as a scaffold in bone regeneration procedures, without the need of a membrane coverage. Further preclinical studies are warrant to optimise the potential of mCM.


2021 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Noritaka Maeta ◽  
Takako Shimokawa Miyama ◽  
Kenji Kutara ◽  
Teppei Kanda ◽  
Ikki Mitsui ◽  
...  

A three-year-old male Pug presented with a three-year history of urolithiasis and repeated urethral obstruction. Biochemical analysis, ultrasonography, and retrograde urethrocystography revealed probable portosystemic shunt and incomplete urethral obstruction due to uric acid ammonium calculi. Enhanced computed tomography (CT) revealed portosystemic shunt and proliferation of the osseous tissue of the os penis, which was surgically removed. Histopathologically, the excised osseous tissue comprised bland lamellar bone without atypia or inflammation. Hyperplasia of the os penis was diagnosed based on the image findings and histopathology. The dysuria improved postoperatively. This is the first report of dysuria associated with non-neoplastic bone hyperplasia of the os penis in a dog. Careful evaluation of the os penis by CT is needed for accurate diagnosis in case of repeated penile urethral obstruction.


Author(s):  
Rachit Gulati ◽  
Shashank Yeshwant Kothari ◽  
Sandeep Kumar Gupt

Heterotopic Ossification (HO) is formation of atypical, lamellar bone within a soft tissue surrounding major joints. It is well documented as a complication following spinal cord injury and traumatic brain injury; however, it is quite rarely seen in lower motor neuron conditions like Guillain-Barre Syndrome (GBS). Here, we present two cases of GBS (both young males) with Bilateral hip pain who were diagnosed HO on the basis of radiological study while still admitted in the Intensive Care Unit (ICU). Both of them had history of mechanical ventilation, tetraparesis and prolonged immobilisation. There are very few reports of HO in GBS and if detected early, it improves the functional outcome.


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